A capillary tube made of glass of radius 0.15
mm is dipped vertically in a beaker filled with
methylene iodide (surface tension = 0.05 Nm^–1,
density = 667 kg m^–3) which rises to height h in
the tube. It is observed that the two tangents
drawn from liquid-glass interfaces (from opp.
sides of the capillary) make an angle of 60^o
with one another. Then h is close to (g = 10 ms^–2)